Part Of: Patent Series -- Patent Application Folios

[PT5035-F] Alternating-Current Rectifier (1911)

[This introductory note covers all of the Patent Application Files for Part V. It is preceded by the folio number of the specific application and the U.S. Patent number (if a patent was issued) or a serial number (if the application was abandoned).]

Folio #813 U.S. Patent #1221981

These files consist of formal patent applications, along with correspondence between Edison's attorneys and the U.S. Patent Office. Some of the folders also contain notes and drawings by Edison; draft specifications in Edison's hand and other specifications with Edison notations; memoranda from Edison to his patent attorneys; and related correspondence authored by or sent to Edison, his associates, and his companies.

During the period 1911-1931 Edison executed 113 successful patent applications relating to primary and storage batteries, business and musical phonographs, disc and cylinder records, the kinetophone (a phonograph and motion picture projector combination), cement, and other subjects. Many of the applications pertain to the Diamond Disc phonograph, which Edison introduced toward the end of 1912. An outline of eighteen patents that he planned to pursue in support of his new phonograph can be found at the beginning of Folio 906. Other technologies for which Edison sought patents, not always successfully, include the use of paraphenylenediamine as condensing agent for shellac (to make phonograph records); chemical processing methods for storage battery components and other products; concrete furniture and other concrete products; projectiles (related to his research for the U.S. Navy during World War I); phonograph reproducers; and automobile electrical systems. Among the thirty-seven patents that he received during the last decade of his life (four others were issued posthumously) are two for rubber processing and one for a radio or telephone receiver based on osmotic action, dubbed the "osmophone" (folio 1231).

Another set of application files for Edison's U.S. patents can be found in the National Archives (Record Group 241, Records of the Patent Office). The National Archives set is nearly complete and is available on microfilm. For that reason, the formal specifications and the correspondence between Edison's attorneys and the Patent Office have not been selected in the case files for the successful applications in the Edison National Historical Park's collection. The selected material from these files consists primarily of notes, drawings, and draft specifications by Edison, along with occasional correspondence to or from Edison, his associates, and his companies. The case files for Edison's abandoned or forfeited applications have been selected in their entirety except for duplicates, printed patents by Edison and other inventors, and other printed material. Several applications by Thomas A. Edison, Jr., have also been selected. The files are arranged in chronological order according to execution date—the date on which the formal application was signed and witnessed.

Courtesy of Thomas Edison National Historical Park.

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